Answers to Countdown Challenge Questions
Discussion of Challenge Question #21 (Day 12B):
Bickering takes energy, and makes it easier for predators to notice a nest. Nestlings that fight usually belong to species that hunt for limited food. When a mother hawk catches a mouse, she might not catch another for several hours, or even a whole day. So if the most aggressive baby gets the food, it is more likely to survive than the meeker babies. But hummingbird mothers are sure to find enough food for both their babies, so there's no need for the babies to waste energy arguing.
The last time we saw them, the babies were facing in opposite directions. Now they are facing the same way!